The only thing that Jenny the transgender stripper could think of wishing for was a pair of boobs. She had been thinking of getting a pair, back before she inherited the wishing stone from her late grandfather, but she wondered why she had waited so long to make the actual wish. After all, it should have been one of the first things on her mind to wish for, right?
So with that, not waiting any longer, she said "I wish I had F-cup breast implants." If she was going to get breasts, might as well go big. Plus, it'll help her get more tips at the club. The stone glowed, granting her wish. A moment later, she was looking in the mirror and admiring her new breasts, now being displayed in her cleavage-baring top.
The thing was, though, since Jenny's existence would, unknown to her, only last for the next seven days, that wish would still be in effect when Jon reverted to normal at the end of the week, meaning he would be a boy with implanted F-cup breasts that he may not be able to get rid of.